Single-mode fiber-compatible plastic-molded surface-contact receptacles

A single-mode fiber-compatible surface-contact (SC) receptacle is fabricated by insert-molding technology with a zirconia sleeve in the mold patterns. The zirconia sleeve, lens holder, and a plastic case consist of the same mold pattern for precise coincidence of the optical axes. Almost all of the case structures are fundamentally cylindrical to disable temperature modifications due to mechanical expansion or deformation. For the same reason, the grade of liquid crystalline polymer is selected carefully. Furthermore, the roof mirror array lens used in the facsimile machine is selected as a graded-index (GRIN) rod lens to reduce costs. The fabrication results show that in this structure, the mechanical removal strength in the zirconia sleeve attained over 50 kg f, and mechanical tolerance is also maintained after more than 1000 plug coupling tests. The fabrication methods are successively suitable for mass production and contributed to the cost effective SC receptacle. This receptacle is compatible not only with multimode fiber but also with single-mode fiber. The total coupling toss in this receptacle equipped with a 1.3-mu m multi-quantum-well laser diode is -6 dB with the single-mode fiber. The contribution due to the GRIN rod lens is -5.5 dB and the excess coupling loss due to the assembly is within -0.5 dB. (C) 1996 Society af Photo-Optical Instrumentation Engineers.